Dear Flying Lawyer,
I repeat the first paragraph of your post.
I'm no engineer so can't improve upon the valid comments made by WNR.
I hope I'm not being unfair, but I can't help wondering whether Lu started his research with an open mind, forming a conclusion based upon the facts which he found - or started with his conclusion, and then selected facts to support it. It does make a difference.
I started my investigation after three years working for Bell and being made aware of the mast bump, rotor loss phenomenon and having participated in an accident investigation of a rotor separation that occured after the helicoptwer landed and was in process of shutting down. But that is a story in itself. If you read my bio it states that I am concerned with the safety of passengers and crew. My interest in Robinsons and their collective problems when I saw a rotor head that was removed from an R22. For a two bladed helicopter the pitch horns lead the blade by approximately 72 degrees instead of 90 degrees on the bell. I got copies of the POHs for the 22 and the 44 as well as the maintenance manual for the 22. I started reading them and found that the pilots were restricted from side slip and out of trim flight. This I firmly believe was a means of covering up the design deficiencies of the rotor head. The design is such that if you fly out of trim or in a side slip the flapping loads would be so severe that the rotor system could be damaged to the point of failure. If the rotor system cannot be flown now in a side slip or out of trim condition then please explain to me how the helicopters could have been certified because in order to be certified they must demonstrate those flight regimes.
This is my personal opinion about Robinson pilots is you have been brain washed
by the Robinson doctrine. There is going to be a safety course that is being taught in the UK by a Robinson instructor.
If anyone reading this attends please ask the man about the 72 pitch horn lead and the 90 degrees of precession of the blades. Ask him how the pilot compensates for this 18 degree difference between the Robinson and the Bell.
[This message has been edited by helidrvr (edited 07 October 2000).]